Dogs and humans share a unique bond, filled with tail wags, playful barks, and sometimes, slobbery licks. If you’re a dog owner, you’ve likely experienced your furry friend showering you with affection in the form of licks. While many pet parents interpret these licks as kisses, the reasons behind this behavior are far more nuanced and fascinating. So, Why Do Dogs Lick Humans? It turns out, this common canine behavior is rooted in a variety of instincts, communication signals, and sensory explorations.
The Science Behind Dog Licking
Licking is deeply ingrained in a dog’s nature. Interestingly, studies reveal that this action triggers the release of endorphins in a dog’s brain. Endorphins are powerful neurotransmitters that have a calming and relaxing effect on dogs (and humans!). This initial release of endorphins is often followed by a surge of dopamine, another neurotransmitter associated with pleasure and motivation. This internal reward system reinforces the licking behavior, making it a comforting and satisfying action for dogs.
Dogs explore their world through licking various objects and surfaces, some of which might seem less appealing to us. So, when it comes to licking humans, the motivations can be quite diverse. It’s not just one simple answer. Dogs lick people for a multitude of reasons, encompassing affection, communication, grooming, exploration of their environment, seeking attention, and even the simple pleasure of taste.
Learned Behavior from Puppyhood
The origins of licking behavior can be traced back to a dog’s early puppyhood. Mother dogs instinctively lick their newborn pups immediately after birth. This licking serves several crucial purposes: cleaning the pups, stimulating their breathing and circulation, and encouraging them to urinate and defecate. For the first few weeks of a puppy’s life, maternal licking is essential for their survival and development. This early experience establishes a fundamental connection between licking and caregiving.
Puppies also learn to use licking as a communication tool within their litter and with older dogs. They may lick older dogs, including their mother, as a sign of appeasement, signaling their submissive and non-threatening intentions. This helps establish a peaceful social hierarchy. Furthermore, puppies lick each other to express affection, offer comfort, and strengthen their bonds with their littermates.
Enhanced Sense of Smell and Taste
While humans rely heavily on taste, dogs have a less developed sense of taste with fewer taste buds. Instead, their sense of smell reigns supreme. Licking plays a crucial role in enhancing a dog’s olfactory experience. By licking, dogs can further investigate and analyze scents, essentially “tasting” smells more intensely. This is why they are often drawn to licking areas of our bodies that are rich in scents and flavors, such as our hands, faces, ears, and feet.
To understand this fascination, it’s helpful to consider the physiology of human sweat. We have two primary types of sweat glands: eccrine and apocrine glands.
- Eccrine glands are distributed widely across the body and are particularly concentrated on the soles of the feet, palms of the hands, forehead, and cheeks. They secrete a thin, watery fluid composed of salt, proteins, and other substances. This fluid is odorless.
- Apocrine glands are found in areas like the armpits and groin, as well as in the ear canals, eyelids, and nostrils. They release a thicker, oily fluid. When this fluid interacts with bacteria on the skin, it produces body odor.
Given this biological cocktail of scents and tastes on our skin, it’s no wonder dogs find licking us so intriguing!
Specific Reasons for Licking Different Body Parts
Dogs don’t just lick randomly; they often target specific areas of our bodies. The reasons behind licking your hands, face, ears, feet, or legs can vary.
Why Dogs Lick Your Hands
Think of your hands as scent magnets. Throughout the day, your hands come into contact with countless objects, people, and environments, collecting a diverse array of smells and flavors. When you return home, your dog sees your hands as a storybook of your day’s adventures, eager to explore each “chapter” through licking. You might have touched other animals, interacted with different people, or handled food, all leaving scent traces on your hands that your dog is keen to investigate.
Additionally, the palms of your hands are rich in eccrine glands, meaning they produce salty sweat. This salty residue is another appealing taste for your dog to enjoy.
Why Dogs Lick Your Face
Similar to hands, your face is constantly exposed to the external environment, accumulating a wealth of interesting smells and tastes. We also frequently touch our faces, transferring even more scents and flavors that pique a dog’s interest. This provides ample reasons for dogs to lick your face.
Your face features both types of sweat glands. Eccrine glands on your cheeks and forehead contribute a salty taste that many dogs find enjoyable. Apocrine glands located on your eyelids and nostrils release a subtle yet distinct odor easily detectable by a dog’s highly sensitive nose.
Furthermore, the area around your lips and mouth carries the enticing aromas and tastes of the food you’ve eaten. This explains why some dogs are particularly inclined to lick your face, even attempting to lick your lips, especially after a meal.
Beyond the sensory appeal, face licking is also often an instinctual social behavior. Dogs lick each other’s faces as a form of mutual grooming, to express affection, and to communicate peaceful intentions or submissiveness. If you react positively to your dog licking your face, you might inadvertently reinforce this behavior, making it more likely to continue.
Why Dogs Lick Your Ears
When your dog licks your ears, it could be for a combination of reasons: taste exploration, grooming, or a display of affection.
The ear canals are home to apocrine glands, which secrete an odor-producing fluid when mixed with skin bacteria. Combined with ceruminous glands that produce earwax, your ears present a unique blend of smells and tastes that can attract your dog.
Dogs engage in ear licking with each other as a form of grooming. Allowing another dog to lick their ears is a vulnerable act, suggesting a high level of trust and comfort between the dogs. When your dog licks your ears, it could be mirroring this grooming behavior, showing you affection and a sense of closeness.
Why Dogs Lick Your Feet
The soles of your feet are densely packed with eccrine glands, making them a significant source of salty sweat. For your dog, your feet can be a readily available source of salty goodness. If you’re ticklish, foot licking can also turn into a playful interaction between you and your dog.
If you laugh or smile when your dog licks your feet, you’re providing positive reinforcement for the behavior. Dogs are quick to learn that certain actions elicit attention from their owners. Foot licking can become a learned behavior to gain your attention, especially when your bare feet are accessible.
Why Dogs Lick Your Legs
If your dog licks your legs, particularly after you’ve showered, they might be attracted to the water droplets on your skin. This isn’t necessarily because they are thirsty, but rather they are interested in the residual scents and tastes left behind by your shower products.
Shampoos, body washes, and shaving creams all leave distinctive scents and tastes on your skin that can pique a dog’s curiosity. If you happen to have any minor cuts from shaving, the scent of blood might also attract your dog, as dogs instinctively lick wounds to clean them.
Even if showering isn’t the trigger, leg licking could be due to lotions you’ve applied, salt residue from exercise, or simply an intriguing scent you’ve unknowingly picked up.
When Is Licking a Problem?
While licking is a normal and natural canine behavior, there are instances where it can become problematic, indicating underlying behavioral or medical issues. Dogs may lick out of boredom. In such cases, increasing enrichment in their environment can help redirect this behavior. Puzzle toys, interactive games, and lick mats can provide mental stimulation and an appropriate outlet for their licking instincts.
However, excessive licking, especially if it occurs frequently in response to specific situations and is difficult to interrupt, can be a sign of anxiety. If a dog excessively licks a person they seem uncomfortable with, it could be their way of trying to soothe themselves, gather information about the person, or even attempt to create distance.
Licking can also be a canine calming signal or a displacement behavior. When dogs feel stressed, anxious, or conflicted, they may use licking as a way to buy time and signal that they are not ready to engage in a situation. The release of endorphins and dopamine during licking can serve as a self-soothing mechanism in anxiety-provoking social interactions. In some cases, excessive licking can be associated with compulsive disorders.
Medically, persistent and focused licking of a specific area of their own body (distinct from general grooming) can be a symptom of underlying health issues like allergies, infections, or pain. If a dog is licking inanimate objects excessively, such as furniture, rugs, or floors, it could potentially indicate gastrointestinal problems.
If you observe any forms of licking that seem problematic, it’s crucial to seek professional help. Start by consulting your veterinarian to rule out any underlying medical conditions. If medical causes are excluded, a certified behavior consultant or a veterinary behaviorist can provide expert guidance in addressing any behavioral components contributing to the excessive licking. Complex cases often benefit from the expertise of a veterinary behaviorist as soon as possible.
In conclusion, why do dogs lick humans? The answer is multifaceted, ranging from instinctual behaviors rooted in puppyhood to complex communication signals and sensory explorations. While most licking is perfectly normal and often a sign of affection and bonding, it’s important to be aware of when licking might indicate an underlying issue requiring professional attention. Understanding the various reasons behind this common canine behavior can deepen our appreciation for our furry companions and strengthen the unique bond we share.
